Delivery of hydrogel compositions as a fine mist

ABSTRACT

Dental compositions are provided that can be delivered as a fine mist and that have the capability of undergoing an increase in viscosity in response to an increase in temperature. In a preferred embodiment, the compositions also have the ability to reverse their viscosity in response to a decrease in temperature.

FIELD OF THE INVENTION

[0001] This invention relates to the delivery as a fine mist of dentaltreatment compositions having viscosities capable of responding to achange in temperature. The invention also relates to devices forapplying the compositions as a fine mist.

BACKGROUND

[0002] In the dental art, the use of a dental treatment composition isgenerally desirable for numerous applications or indications including,for example, treatment of caries, calculus build-up, xerostomia, staineddentition, bad breath, gingivitis, bacterial infections, oral pain orsensitivity such as sore throat, canker sores, and bums. To attainproper application and effectiveness at the desired location, it isdesirable that the composition be controllable and slow to flow awayfrom it target site. Thus a high viscosity dental composition in theoral environment would be quite useful.

[0003] Currently available dental compositions are provided in seeminglyextreme viscosity states. That is, there exist compositions that havevery low viscosities as well as compositions that are highly thickenedand therefore possess high viscosity. Those with low viscosities aredifficult to control and have tendencies to flow away from the targetsite once it is applied. Compositions with high viscosities aredifficult to extrude through a small orifice.

[0004] Certain dental compositions may use thickeners such as fumedsilica and/or polymer additives such as polyvinyl alcohols,polyethyleneglycols, and the like. Problems encountered in using thesethickeners include aging, which results in non-homogenous gels whichmake handling difficult, and shear thinning, which reduces the viscosityof a gel when extruded through an orifice and thinning at elevatedtemperatures. Thinning can result in a material that drips from thedesired point of application.

[0005] Dental etching compositions, which are suitable for etching hardtissue and include an acid and a thermally responsive viscositymodifier, are disclosed in PCT International Publication No. WO00/28946. Dental whitening compositions that include a whitening agentand a thermally responsive viscosity modifier are disclosed in PCTInternational Publication No. WO 00/28955. Such compositions are capableof being applied to a target site through an orifice (e.g., a syringe),whereupon they undergo an increase in viscosity in response to anincrease in temperature. The increase in viscosity is useful inpreventing the dental compositions from flowing away from the targetarea of application.

[0006] There exists a need in the art for convenient methods ofdelivering dental compositions to target sites, and for the compositionsto remain at the target application area after delivery.

SUMMARY OF THE INVENTION

[0007] In one aspect, the present invention provides a method ofapplying a dental composition in the oral environment using an aqueousdental composition including about 10% by weight to about 50% by weightof a thermally responsive viscosity modifier and water, wherein thecomposition is in a low viscosity state at a pre-treatment temperatureand a highly viscous state at a treatment temperature that is higherthan the pre-treatment temperature. The method includes spraying thecomposition as a fine mist onto a surface, wherein the composition is atthe pretreatment temperature and in the low viscosity state prior tobeing sprayed onto the surface, allowing the composition to warm to thetreatment temperature and increase in viscosity to the highly viscousstate wherein the viscosity of the composition at the treatmenttemperature is at least about 10 times the viscosity of the compositionat the pre-treatment temperature, and allowing the composition to remainon the surface. Preferably the pre-treatment temperature at most aboutroom temperature and the treatment temperature is about bodytemperature. The dental composition may optionally include adjuvantssuch as acids, whitening agents, fluoride sources, stability promoters,anti-microbial agents, anti-fungal agents, anti-calculus forming agents,preservatives, adhesive modifiers, fillers, dyes, detection indicators(e.g., for caries, gingivitis, and the like), cariostatic agents,flavorings, sweeteners, medicaments, sodium bicarbonate, specificenzymes, hydrating agents, and breath fresheners. The dental compositionoptionally may also include a propellant.

[0008] In another aspect, the present invention provides a spray deviceincluding a container; an aqueous dental composition in the container,the composition including about 10% by weight to about 50% by weight ofa thermally responsive viscosity modifier and water, wherein thecomposition is in a low viscosity state at a pre-treatment temperatureand a highly viscous state at a treatment temperature that is higherthan the pre-treatment temperature; and a sprayer in fluid communicationwith the dental composition, the device being capable of spraying thedental composition as a fine mist into the oral environment. Optionally,the device may further include a propellant.

[0009] In another aspect, the present invention provides a fine mist ofa dental composition in the oral environment, the composition includingabout 10% by weight to about 50% by weight of a thermally responsiveviscosity modifier and water, wherein the composition is in a lowviscosity state at a pre-treatment temperature and a highly viscousstate at a treatment temperature that is higher than the pre-treatmenttemperature.

[0010] In another aspect, the present invention provides a dentalcomposition capable of being sprayed as a fine mist into the oralenvironment, the composition including about 10% by weight to about 50%by weight of a thermally responsive viscosity modifier; water; and apropellant, wherein the composition is in a low viscosity state at apre-treatment temperature and a highly viscous state at a treatmenttemperature that is higher than the pre-treatment temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a graphic illustration of the viscosity versustemperature data as described in Preparative Example 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention provides a dental composition in a lowviscosity state prior to application onto an oral surface, but whichalso is highly viscous, thick and controllable at the target site. Thesecompositions are easily dispensed, applied, and manipulated when handledby the user, and are easily controlled upon application to the targetsite. Because the composition has a low viscosity initially at apre-treatment temperature, it is easily delivered as a fine mist to theintended site. In addition, production of low viscosity compositions mayprovide easier processing and greater uniformity and consistency.

[0013] Compositions of this invention are particularly suitable for usein the intraoral environment where a composition having a pre-treatmenttemperature at or lower than ambient (room temperature) is applied to auser's oral surface that is near or at oral temperature of about 30° C.to about 39° C. For certain dental applications, it is preferred thatthe composition be thermally reversible. In that application, thecomposition not only has the ability to increase its viscosity at anelevated intra-oral temperature, but also reverses or decreases itsviscosity upon a decrease in temperature.

[0014] The capacity of the dental composition to thicken at oraltemperatures is a critical feature of the invention, for it is in thisproperty that many of the disadvantages of previous approaches areovercome. The dissipative characteristic of liquid solutions is avoidedsince the compositions herein experience thickening at the site oftreatment. Moreover, the problems of formulation, handling, delivery andapplication of viscous compositions are overcome since the presentcompositions may be free-flowing liquids prior to treatment.

[0015] A “semi-solid,” as used herein, is a material whose physicalstate is between the solid and liquid state, in which pure or mixedsolvent or solution is entrained within a network, and can alternativelybe considered a gel. By “pure or mixed solvent and/or solution,” asstated herein, it is recognized that a mixture of solvents may beabsorbed by the network. Additionally, the solvent may include salts orother additives so as to form a solution, which may also be absorbed orentrained within the network.

[0016] “Thickening” as used herein, is where a composition undergoes asubstantial increase in the viscosity of the composition. The degree ofthickening is dependent on the initial viscosity of the composition.

[0017] As used herein, a “fine mist” or “aerosol” means fine droplets ofa liquid sprayed into the air or, alternatively, a gaseous suspension ofa fine liquid and/or colloidal particles

[0018] In a preferred embodiment of the invention, the initial viscosityof the composition may be low enough such that the composition is in aliquid state. Subsequently, upon exposure to a temperature of about nearor at oral temperature, the viscosity increases to result in a thickenedcomposition. A viscosity increase in the range of about 10- to about100-fold can be experienced when the initial viscosity is such that thecomposition is a liquid. Thus, for example, a composition in a liquidstate may have a viscosity of about 0 to about 7000 poise. In responseto an increase in temperature, the viscosity of the composition canincrease to at least about 10,000 poise. Upon the lowering of thetemperature, the composition preferably has the ability to reverse itsviscosity and return to flow properties of a liquid.

[0019] The pre-treatment temperature is the temperature at which thecomposition is subjected to prior to application or treatment. The rangefor the pre-treatment temperature can be about 5° C. to about 29° C.,although there may be certain instances where the temperature may beoutside this range. Having a pre-treatment temperature at about 20° C.to about 25° C. allows the composition to be easily stored at ambient orroom temperature. Alternatively, the compositions of the invention canalso be advantageously stored at lower, refrigeration pre-treatmenttemperatures of about 5° C. to about 10° C. to provide improvedstability and shelf life.

[0020] The treatment temperature is the temperature at which thecomposition is exposed to during intraoral application. This can be ator near body temperature, or about 30° C. to about 39° C.

[0021] In accordance with the invention, the dental composition consistsof a water-miscible, physiologically compatible medium that is liquid atambient temperature below about 30° C. and experiences thickening atoral temperatures above about 30° C. It has been found that acomposition having a thickening transition temperature in the range offrom about 25° C. to about 40° C. is useful in the practice of thepresent invention. Preferably, the thickening occurs in a temperaturerange of from about 25° C. to about 39° C., and more preferably fromabout 30° C. to about 35° C.

[0022] Compositions of this invention are comprised of water and one ormore polymeric substances that provide the desired viscosity increase atthe desired elevated temperature range in the composition. Optionally,adjuvants may be added to the composition. Preferably, the compositionof this invention should be physiologically compatible so that noadverse reaction occurs if the dental composition comes in contact withhuman tissue or fluids.

[0023] As used herein, a “thermally responsive viscosity modifier” isone or more polymeric substances that provide the composition orpolymeric system the capability of substantially changing its viscosityin response to a change in temperature. Suitable polymeric substancesuseful as thermally responsive viscosity modifiers includepolyoxyalkylene polymers, particularly the polymeric surfactantsavailable under the tradename PLURONIC. This class of polymers isavailable commercially from BASF Wyandotte Corporation. Otherpolyoxyalkylene polymers may also be useful as a thermally-responsivecomposition material.

[0024] A preferred dental composition in accordance with this inventioncomprises an aqueous solution of a selectedpolyoxyethylene-polyoxypropylene block copolymer. A compositioncomprising polyoxyethylene-polyoxypropylene block copolymers in whichthe number of polyoxyethylene units is at least about 50% of the numberof units in the total molecule, and the block copolymer having anaverage molecular weight of from about 1100 to about 15,500 has beenfound to be particularly useful. It is more preferable that acomposition comprises about 70% polyoxyethylene units of the totalnumber of monomeric units in the copolymer and the copolymer has anaverage molecular weight of about 11,500. PLURONIC F-127 is a materialthat meets these criteria.

[0025] The PLURONIC polymers are closely related block copolymers thatmay be generically classified as polyoxypropylene-polyoxyethylenecondensates that terminate in primary hydroxyl groups. These polymersare formed by the condensation of propylene oxide into a propyleneglycol nucleus followed by the condensation of ethylene oxide onto bothends of the polyoxypropylene base. The polyoxyethylene hydrophilicgroups on the ends of the base pre-polymer are controlled in length toconstitute from about 10% to about 80% by weight of the final polymer.

[0026] The PLURONIC polymer series of products may be representedempirically by the formula: HO(C₂H₄O)_(a)(C₃H₆O)_(b)(C₂H₄O)_(c)H where aand c are statistically equal.

[0027] The concentration of the block copolymers is an importantparameter and can be formulated in such a manner corresponding to theother components' concentrations. By adjusting the concentration of thecopolymer to accommodate other solutes present in the composition, anydesired liquid to semi-solid transition temperature in the criticalrange of above ambient temperature and below body temperature can beachieved. Thus, the principal consideration is the selection of aconcentration which, in conjunction with all of the constituents of thetotal composition, will provide a liquid to semi-solid transitiontemperature in the required range.

[0028] It has been found that a useful block copolymer concentration isfrom about 5% by weight to about 40% by weight (wt. %) of thecomposition, particularly from about 15% by weight to about 26% byweight of the composition. Excellent results have been obtained usingaqueous solutions having from about 17% by weight to about 29% by weightof PLURONIC F-127. Increased polymer concentrations may be required inhighly acidic systems to affect the same results as in a less acidicsystem so that, in optimizing the thickening or gelation characteristicsfor a system, the pH of the solution must be taken into account.

[0029] Particularly preferred polymers for the present invention are thePLURONIC F-127 and F-108. These viscosity modifiers are block copolymersof ethylene oxide and propylene oxide. Thickening tendencies of blockcopolymers increase as ethylene oxide content and total molecular weightincrease. Thermally responsive block copolymers have been disclosed inU.S. Pat. Nos. 4,474,751; 4,474,752; 5,441,732; and 5,252,318, as wellas the Product Catalog, “BASF Performance Chemicals,” all the teachingsof which are incorporated by reference herein. These block copolymersoffer extremely low toxicity and a high degree of mildness forapplications involving human contact.

[0030] The concentration of water in the composition can be in the rangeof from about 30% by weight to about 90% by weight of the composition.Preferably, water can exist in the range of about 40% by weight to about80% by weight of the composition. The water used in forming the aqueoussolution is preferably purified, as by distillation, filtration,ion-exchange, or the like.

[0031] Co-solvents may be used, including solutions comprising a polyolcomponent such as propylene glycol or polyethylene glycol. Glycerin mayalso be used as a constituent of the composition.

[0032] The substantial moisture content of the compositions of thepresent invention provides the ability to easily deliver or apply a finemist of a gel-on-contact aqueous material that provides substantialhydration of tissues that are subject to dehydration. By using a finemist spray or aerosol delivery, it is possible to quickly andefficiently treat a relatively large surface area within the oral cavitywith subsequent long-term retention upon gellation on the warm tissues.Of particular utility and interest is the ability to easily deliverhydrating solutions via a spray for treating xerostomia (dry mouth)wherein the compositions are readily retained for extended periods.Other benefits include a soothing and cooling effect due to thelong-term evaporation of moisture, and the ability to protect sore,ulcerated, or burned tissues with a protective aqueous gel.

[0033] Optionally, adjuvants can be added to the composition for variouspurposes. Adjuvants may include active agents and additives. Activeagents include, but are not limited to, whitening agents, fluoridesources, antimicrobials (e.g., antibacterials), enzymes (e.g., glucoseoxidase, lactoperoxidase, and lysozymes), breath fresheners, localanesthetics, clotting agents, acid neutralizers (e.g., baking soda),cariostatic agents, bleaching agents, etching agents, medicaments,anti-calculus agents, and the like. Particularly useful active agentsfor delivery as a fine mist into the oral cavity include those forhydration of xerostomic patients (i.e., drymouth), prevention andtreatment of halitosis (i.e., bad breath), treatment of periodontaldisease, caries reduction, and oral coatings (optionally with localanesthetics) for irritated or ulcerated tissues such as canker sores orsore throat. Of particular interest are enzymes that include, forexample, glucose oxidases and lactoperoxidases. Additives include, butare not limited to, fillers, flavorings, colorants, dyes, detectionindicators (e.g., for caries, gingivitas, and the like), bufferingagents, thixotropes, polyols, and the like. Additives may also beincluded in the composition to promote the stability of the formulation.Antimicrobial agents, antifungal agents, and preservatives may be addedto the composition to improve shelf-life. Of particular interest is theapplication of aqueous compositions that remain localized at the desiredsite for extended time periods while providing the desired therapeuticeffect. Especially significant is the ability to deliver thermallygellable aqueous liquids (optionally containing an adjuvant) to the oralcavity as a fine mist spray.

[0034] In the practice of the present invention, the oral cavity tissuesthat can be treated include human and animal soft and hard tissues. Softtissues include for example, mucosal and gingival tissues. Hard tissuesinclude, for example, teeth and their component parts (e.g., enamel,dentin, and cementum). The compositions disclosed in the presentapplication may be applied to the oral environment as a fine mist oraerosol by any suitable means known in the art (e.g., U.S. Pat. No.5,078,129). For example, the compositions may be placed in a spraybottle and delivered with a hand pump. Alternatively, the compositionsmay be placed in a container with a propellant (e.g., air, nitrogen,carbon dioxide, and hydrocarbons) and be delivered using a pressurizedspray can. In either case, the composition is passed through a fineorifice to form the fine mist.

[0035] Examples of compositions that are useful by application as a finemist in the oral environment are those including a peroxide. Dentalcompositions including a peroxide are useful in applications including,for example, those in which the peroxide serves as an antibacterialagent (e.g., treatment of halitosis, xerostomia, and oral infections)and the whitening of teeth. Preferred peroxides include hydrogenperoxide, carbamide peroxide (CO(NH₂)₂H₂O₂, a hydrogen peroxide ureacomplex), hydrogen peroxide salts (e.g., calcium salt and sodium salt),and combinations thereof. These peroxides are also known by alternativenames, including urea hydrogen peroxide, hydrogen peroxide carbamide, orperhydrol-urea. Alternatively, sodium hypochlorite may be suitable insimilar applications. Preferred concentrations of peroxide in thecomposition can vary depending upon its reactivity and intended use.With carbamide peroxide, for example, the preferred concentration forsome applications is about 3% to about 40%, with about 4% to about 21%being most preferred. In the case of hydrogen peroxide, which is morereactive than carbamide peroxide, the preferred concentration for someapplications is about 2% to about 10%.

[0036] Where the dental compositions are thermally reversible, thecomposition can be readily removed from the oral tissue by cooling thematerial below the liquid to semi-solid transition temperature, thusreversing the thickening effect. This can be accomplished with coolwater or other physiologically compatible liquid. Alternatively, theconcentrations of the components in the composition may be adjusted anddiluted by adding water or other liquid solution. By adjusting theconcentrations of the components, the transition temperature iscorrespondingly adjusted, and thus provides the user the ability toremove the composition even with warm solutions. Water or other liquidsolutions may be administered through a rinsing cup, squirt bottle, aliquid dispensing dental tool, spray pump, aerosol, or any other liquiddispensing device that can provide solution to the oral environment.Preferably, administering cool or cold water provides a significantdecrease in viscosity. Alternatively, the gelled composition may bebrushed, wiped, or blown off.

[0037] These and other aspects of the invention are illustrated by thefollowing examples, which should not be viewed as limiting in scope.Unless otherwise indicated, all molecular weights are number averagemolecular weights and all ratios, parts and percentages are by weight.

EXAMPLES Preparation of the Stock Solution 1

[0038] An aqueous stock solution containing approximately 15% hydrogenperoxide(H₂O₂) was prepared by transferring 5 grams of a 30% H₂O₂ (J. T.Baker) and 5 grams of distilled water to a glass vial. The stocksolution was mixed thoroughly.

Preparation of Stock Solution 2

[0039] An aqueous stock solution containing approximately 20% ureahydrogen peroxide (carbamide peroxide) was prepared by transferring 4grams of 97% urea hydrogen hydrogen peroxide (Sigma) and 16 grams ofdistilled water to a glass vial. The stock solution was mixedthoroughly. (The hydrogen peroxide content of the urea hydrogen peroxidewas about 35%). Stock solution contained about 7% H₂O₂.

Preparative Example 1

[0040] A thermally-reversible hydrogen peroxide composition was preparedby transferring the ingredients below to a glass vial and mixingthoroughly until a colorless and transparent liquid solution wasobtained. Stock Solution 1 1.60 grams PLURONIC F127 (BASF) 0.40 grams2.00 grams

[0041] The above solution contained approximately 12% hydrogen peroxide,68% water and 20% PLURONIC F127. The glass vial containing the liquidperoxide solution was warmed to body temperature by holding the vial ina human hand. Following about one to two minutes, the liquid wastransformed into a colorless, transparent composition that did not flowupon inverting the vial. The vial was allowed to cool to roomtemperature wherein the composition was transformed back to the lowviscosity state. This cycle was repeated several times with the sameoutcome.

[0042] The liquid and semi-solid (gel) states were bothsemi-quantitatively evaluated for hydrogen peroxide utilizing hydrogenperoxide analysis strips. The analysis utilized “EM Quant Peroxide TestStrips” (EM Science Gibbstown, N.J., Catalog No. 10011-1). Thecompositions were evaluated according to the manufacturer's directions.

[0043] Results of the tests indicated that both the liquid andsemi-solid states contained significant amounts of available peroxide.

[0044] The same sample was re-evaluated 2 months later and found tostill exhibit thermally-reversible characteristics and comparablehydrogen peroxide levels based on the semi-quantitative analysis.

Preparative Example 2

[0045] A thermally reversible composition containing urea hydrogenperoxide was prepared by transferring the ingredients below to a glassvial and mixing thoroughly until a colorless and transparent liquidsolution was obtained. Stock Solution 2 4.00 grams PLURONIC F127 (BASF)1.00 grams 5.00 grams

[0046] The above solution contained approximately 16% urea hydrogenperoxide (or about 5.6% hydrogen peroxide), 64% water and 20% PLURONICF127. The glass vial containing the liquid peroxide solution was warmedto body temperature by holding the vial in a human hand. After about 1minute, the liquid transformed to a colorless, transparent compositionthat did not flow upon inverting the vial. The vial was allowed to coolto room temperature wherein the semi-solid composition was transformedback to the low viscosity state. This cycle was repeated several timewith the same outcome.

[0047] The liquid and semi-solid states were both semi-quantitativelyevaluated for hydrogen peroxide utilizing hydrogen peroxide analysisstrips, EM Quant Peroxide Test Strips (EM Science; Gibbstown, N.J.,Catalog No. 10011-1), according to the manufacturer's directions. Boththe liquid and semi-solid states indicated the presence of significantamounts of available peroxide.

[0048] The same sample was re-evaluated 9 days later and found to stillexhibit thermally-reversible characteristics and comparable hydrogenperoxide levels based on the semi-quantitative analysis.

[0049] Table 1 summarizes the results of the two previous examples. The“+” indicates an increase in the viscosity. The “−” indicates a decreasein the viscosity. The presence of hydrogen peroxide as indicated in thetable are the results obtained from the semi-quantitative test using theEM Quant Peroxide Test Strips and test method. TABLE 1 35° C. 25° C.H₂O₂ 35° C. viscosity 25° C. viscosity H₂O₂ Present % Peroxide viscosity@ 9 days viscosity @ 9 days Present @ 9 days Preparative 12 + + − − YesYes Example 1 Preparative 16 + + − − Yes Yes Example 2

Preparative Example 3

[0050] Several compositions were evaluated for viscosity as a functionof temperature. The compositions are described below: TABLE 2Comparative Sample A Physical Physical parts by % by AppearanceAppearance Component weight (g) weight at 23° C. at body temp Urea 20 20Low viscosity, Low hydrogen colorless liquid viscosity, peroxideColorless Water 80 80 liquid

[0051] TABLE 3 Sample B Parts by Physical Physical weight % byAppearance at Appearance at Component (g) weight 23° C. Body temp Ureahydrogen 20 16 Low viscosity, non-flowing, peroxide Colorless liquidcolorless gel Water 80 64 PLURONIC F-127 25 20

[0052] TABLE 4 Sample C Physical Physical Parts by % by Appearance atAppearance at Component weight (g) weight 23° C. body temp Urea hydrogen1.6 14.7 Non-flowing, Non-flowing, peroxide colorless gel colorless gelWater 6.4 58.7 PLURONIC 2.0 18.3 F-127 CAB-O-SIL 0.9  8.3 M-5* (fumedsilica)

[0053] Samples were further evaluated for viscosity as a function oftemperature between 15° C. and 45° C. utilizing a Rheometrics RDA IIRheometer. Complex viscosity, η* (units of measure is in Poise), versustemperature data were obtained using a controlled strain rheometer(“RDA2”, Rheometrics Scientific, Piscataway, N.J.). A parallel plategeometry was used with a plate diameter of 25 mm and a gap ofapproximately 1 mm. Samples were subjected to an oscillatory strain of10% applied at a frequency of 1 rad/sec while the temperature was rampedfrom 15° C. and 45° C. (3° C./min).

[0054] Set out below is the RDA viscosity data. FIG. 1 illustrates thataqueous compositions containing PLURONIC F127 polymer exhibit arelatively sharp increase in viscosity upon warming from roomtemperature to about 45° C. Sample 15° C., which exhibitedsemi-solid-like characteristics at room temperature (due to theincorporation of a fumed silica), also increased substantially upon anincrease in temperature. TABLE 5 A B C Temp η* Temp η* Temp η* ° C. P °C. P ° C. P 14.02 9.75424 17.88 2308.56 18.5 52951.5 14.28 3.35258 17.882379.72 18.3 42757.9 15.36 7.33292 18.54 2587.46 18.79 41559.9 17.283.46242 19.42 3111.41 19.64 41144.7 19.46 5.85152 20.91 3711.59 20.7641347.4 21.12 5.79953 22.36 4580.71 22.09 42047 22.89 7.09599 23.725661.42 23.51 43615.7 24.91 4.19887 25.46 7221.65 24.04 45494.3 26.310.87001 26.85 8940.38 26.03 48768.7 28.23 3.13629 28.73 25375.6 27.9455250.6 30.12 4.57411 30.7 29698.2 29.57 82062.6 31.6 4.7215 32.0733651.8 31.31 94988.5 33.2 9.01765 33.57 37181.2 32.83 1.04E+05 35.028.0025 35.22 40557.8 34.36 1.09E+05 36.75 2.94618 36.89 43766.3 36.091.13E+05 38.44 4.24626 38.43 46677.4 37.49 1.20E+05 40.85 1.08273 40.0149322.7 38.95 1.26E+05 42.92 5.04081 41.84 52296.6 40.7 1.32E+05 43.5254490.4 42.2 1.36E+05 43.9 1.39E+05

Example 1

[0055] An oral hydration composition containing 18 parts PLURONIC F127and 82 parts water was prepared by combining and thoroughly mixing theingredients at approximately 5° C. The resultant homogeneous compositionwas a liquid at between 5° C. and room temperature (e.g., about 25° C.).The liquid was transferred to a vial fitted with hand pumped aerosoldispenser. The composition was easily dispensed as a fine mist at roomtemperature. The composition was sprayed onto a human hand wherein thespray gelled instantaneously on the tissue. In a similar manner, the gelcould also be sprayed as a fine mist onto a surface in the oralenvironment. The hydrogel composition remained an immobile gel andprovided a cooling effect over time. A similar, water-only solution wassimilarly sprayed onto the human hand wherein the liquid flowed andfailed to remain localized.

Example 2

[0056] An oral fluoride composition containing 18 parts PLURONIC F127,90 parts water and 1 part sodium fluoride was prepared by combining andthoroughly mixing the ingredients at approximately 5° C. The resultanthomogeneous composition was a liquid at between 5° C. and roomtemperature (e.g., about 25° C.). The liquid is transferred to a vialfitted with hand pumped aerosol dispenser. The composition is easilydispensed as a fine mist at room temperature. The composition is sprayedonto an artificial tooth heated to about 37° C. wherein it forms animmobile gel on contact with the tooth. Alternatively, the liquid can besprayed onto a tooth or into an oral cavity as a fine mist.

Example 3

[0057] An anti-bacterial, enzymatic oral hydration composition forxerostomic applications was prepared by combining 2.4 parts mouthwashavailable under the trade designation BIOTENE from Laclede ResearchLaboratories (Rancho Dominguez, Calif., and containing lysozyme,lactoferrin, glucose oxidase, lactoperoxidase, water, xylitol,hydrogenated starch, propylene glycol, hydroxyethyl cellulose, aloevera, peppermint, poloxamer 407, calcium lactate, sodium benzoate andbenzoic acid), 0.9 parts PLURONIC F127, and 2.5 parts water andthoroughly mixing the ingredients at approximately 5° C. The resultanthomogeneous composition was a liquid at between 5° C. and roomtemperature (e.g., about 25° C.). The liquid is transferred to a vialfitted with hand pumped aerosol dispenser. The composition is easilydispensed as a fine mist at room temperature. The composition is sprayedonto an artificial tooth heated to about 37° C. wherein it forms animmobile gel on contact with the tooth. Alternatively, the liquid can besprayed onto a tooth or into an oral cavity as a fine mist.

Example 4

[0058] An oral liquid composition containing 18 parts PLURONIC F127, 82parts water and 1 part sodium bicarbonate (baking soda) was prepared bycombining and thoroughly mixing the ingredients at approximately 5° C.The resultant homogeneous composition was a liquid at between 5° C. androom temperature (e.g., about 25° C.). The liquid is transferred to avial fitted with hand pumped aerosol dispenser. The composition iseasily dispensed as a fine mist at room temperature. The composition issprayed onto an artificial tooth heated to about 37° C. wherein it formsan immobile gel on contact with the tooth. Alternatively, the liquid canbe sprayed onto a tooth or into an oral cavity as a fine mist.

What is claimed is:
 1. A method of applying a dental composition in theoral environment using an aqueous dental composition comprising about10% by weight to about 50% by weight of a thermally responsive viscositymodifier and water, wherein the composition is in a low viscosity stateat a pre-treatment temperature and a highly viscous state at a treatmenttemperature that is higher than the pre-treatment temperature,comprising: spraying the composition as a fine mist onto a surface,wherein the composition is at the pretreatment temperature and in thelow viscosity state prior to being sprayed onto the surface, allowingthe composition to warm to the treatment temperature and increase inviscosity to the highly viscous state wherein the viscosity of thecomposition at the treatment temperature is at least about 10 times theviscosity of the composition at the pre-treatment temperature, andallowing the composition to remain on the surface.
 2. The method ofclaim 1 wherein the pre-treatment temperature is at most about roomtemperature.
 3. The method of claim 1 wherein the treatment temperatureis about body temperature.
 4. The method of claim 1 wherein thethermally responsive viscosity modifier is a polyoxyalkylene polymer. 5.The method of claim 1 wherein the viscosity of the composition at thetreatment temperature is about 10 times to about 100 times the viscosityof the composition at the pre-treatment temperature.
 6. The method ofclaim 1 wherein the composition decreases in viscosity upon cooling fromthe treatment temperature.
 7. The method of claim 6 further comprisingremoving the composition from the surface by cooling the compositionfrom the treatment temperature.
 8. The method of claim 7 wherein thecomposition is cooled by application of a cool liquid.
 9. The method ofclaim 8 wherein the liquid comprises water.
 10. The method of claim 1wherein spraying the composition onto a surface comprises spraying thecomposition onto hard tissue.
 11. The method of claim 1 wherein sprayingthe composition onto a surface comprises spraying the composition ontosoft tissue.
 12. The method of claim 11 wherein allowing the compositionto remain on the surface hydrates the surface.
 13. The method of claim 1wherein the dental composition comprises about 17% by weight to about40% by weight of a thermally responsive viscosity modifier.
 14. Themethod of claim 1 wherein the composition further comprises an adjuvant.15. The method of claim 14 wherein the adjuvant is selected from thegroup consisting of acids, peroxides, fluoride sources, medicaments,stability promoters, acid neutralizers, preservatives, adhesivemodifiers, fillers, dyes, flavorings, sweeteners, saliva inducers, andbreath fresheners.
 16. The method of claim 14 wherein the adjuvant isselected from the group consisting of anti-microbial agents,anti-calculus agents, anti-fungal agents, cariostatic agents, localanesthetics, enzymes, and sodium bicarbonate.
 17. The method of claim 1wherein the composition further comprises a propellant.
 18. The methodof claim 1 wherein the aqueous composition further conprises a salt. 19.A spray device comprising: a container; an aqueous dental composition inthe container, the composition comprising about 10% by weight to about50% by weight of a thermally responsive viscosity modifier and water,wherein the composition is in a low viscosity state at a pre-treatmenttemperature and a highly viscous state at a treatment temperature thatis higher than the pre-treatment temperature; and a sprayer in fluidcommunication with the dental composition, the device being capable ofspraying the dental composition as a fine mist into the oralenvironment.
 20. The device of claim 19 wherein the device furthercomprises a propellant.
 21. A fine mist of a dental composition in theoral environment, the composition comprising about 10% by weight toabout 50% by weight of a thermally responsive viscosity modifier andwater, wherein the composition is in a low viscosity state at apre-treatment temperature and a highly viscous state at a treatmenttemperature that is higher than the pre-treatment temperature.
 22. Adental composition capable of being sprayed as a fine mist into the oralenvironment, the composition comprising: about 10% by weight to about50% by weight of a thermally responsive viscosity modifier; water; and apropellant, wherein the composition is in a low viscosity state at apre-treatment temperature and a highly viscous state at a treatmenttemperature that is higher than the pretreatment temperature.